WARNING in register_lock_class

[syzbot]

Hello,

syzkaller hit the following crash on
6084b576dca2e898f5c101baef151f7bfdbb606d
git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/master
compiler: gcc (GCC) 7.1.1 20170620
.config is attached
Raw console output is attached.
C reproducer is attached
syzkaller reproducer is attached. See https://goo.gl/kgGztJ
for information about syzkaller reproducers


WARNING: CPU: 0 PID: 13098 at kernel/locking/lockdep.c:718
arch_local_save_flags kernel/locking/lockdep.c:687 [inline]
WARNING: CPU: 0 PID: 13098 at kernel/locking/lockdep.c:718
look_up_lock_class kernel/locking/lockdep.c:709 [inline]
WARNING: CPU: 0 PID: 13098 at kernel/locking/lockdep.c:718
register_lock_class+0x5a2/0x5d0 kernel/locking/lockdep.c:740
Kernel panic - not syncing: panic_on_warn set ...

CPU: 0 PID: 13098 Comm: syzkaller182681 Not tainted
4.15.0-rc3-next-20171214+ #67
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0xe9/0x14b lib/dump_stack.c:53
panic+0x10e/0x2f8 kernel/panic.c:183
__warn+0x14e/0x150 kernel/panic.c:547
report_bug+0x11e/0x1a0 lib/bug.c:184
fixup_bug.part.11+0x17/0x30 arch/x86/kernel/traps.c:177
fixup_bug arch/x86/kernel/traps.c:246 [inline]
do_error_trap+0x14a/0x180 arch/x86/kernel/traps.c:295
do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:314
invalid_op+0x22/0x40 arch/x86/entry/entry_64.S:1079
RIP: 0010:arch_local_save_flags kernel/locking/lockdep.c:687 [inline]
RIP: 0010:look_up_lock_class kernel/locking/lockdep.c:709 [inline]
RIP: 0010:register_lock_class+0x5a2/0x5d0 kernel/locking/lockdep.c:740
RSP: 0018:ffffc90001e2fb38 EFLAGS: 00010086
RAX: 0000000000000000 RBX: ffffffff83b1e790 RCX: 0000000000000000
RDX: ffffffff83ff0bb0 RSI: 00000000000002b0 RDI: 0000000000000000
RBP: ffffc90001e2fba0 R08: 0000000000000000 R09: ffffffff8121b4f4
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: ffff88021388a4b8 R15: 0000000000000000
__lock_acquire+0xb4/0x1430 kernel/locking/lockdep.c:3314
lock_acquire+0xbf/0x220 kernel/locking/lockdep.c:3914
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0x56/0x70 kernel/locking/spinlock.c:152
remove_wait_queue+0x14/0x60 kernel/sched/wait.c:50
ep_remove_wait_queue fs/eventpoll.c:595 [inline]
ep_unregister_pollwait.isra.7+0x79/0x1f0 fs/eventpoll.c:613
ep_free+0x71/0x140 fs/eventpoll.c:830
ep_eventpoll_release+0x26/0x30 fs/eventpoll.c:862
__fput+0x120/0x270 fs/file_table.c:209
____fput+0x15/0x20 fs/file_table.c:243
task_work_run+0xa3/0xe0 kernel/task_work.c:113
exit_task_work include/linux/task_work.h:22 [inline]
do_exit+0x3e6/0x1050 kernel/exit.c:869
do_group_exit+0x60/0x100 kernel/exit.c:972
SYSC_exit_group kernel/exit.c:983 [inline]
SyS_exit_group+0x18/0x20 kernel/exit.c:981
entry_SYSCALL_64_fastpath+0x1f/0x96
RIP: 0033:0x446259
RSP: 002b:00000000007efa18 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00000000ffffffff RCX: 0000000000446259
RDX: 0000000000446259 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 000000000000665e
R10: 0000000000000000 R11: 0000000000000202 R12: 00000000000026e9
R13: 000000000000665e R14: 0000000000000000 R15: 0000000000000000
Dumping ftrace buffer:
(ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..


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[Eric Biggers]

Fixed by commit f5cb779ba163:

#syz fix: ANDROID: binder: remove waitqueue when thread exits.

- Eric